All The King's Men: Foil 1 key example

The most notable difference between Jack and Cass is over religion and morality. While they both have lives full of mistakes and betrayal, Cass turns late in his life to religion, whereas Jack retains his atheism throughout his entire life. One might expect that this would make Cass more morally pure than Jack—but Cass's affair with Annabelle Trice is more morally reprehensible, by far, than anything Jack does in the novel. Jack, in fact, is relatively innocent in the novel, especially in matters of love, if occasionally a bit dismissive and rude; the devout Cass, in contrast, lives a life following his desires freely and amorally. As such they form moral opposites.

Cass thus helps to clarify Jack's character; in turn, Jack is fascinated by Cass and continues to write about him years after anyone else cares much about him. This unshakable interest also shows Jack's belief that, by understanding the past, he can understand the present—an instinct of Jack's also shown after the revelation of Anne's affair with Willie, when he attempted to examine his and Anne's whole relationship for possible causes. Jack is, indeed, a writer and a historian first and knows a good story, in Cass's star-crossed love, when he sees one.

Cass Mastern, and Jack's dissertation on him, also demonstrate the narrator's unique devotion to what he sees as the "truth." As a graduate student at Louisiana State, Jack knew the "facts" of Mastern's life but felt that he could not represent the "truth" of the events of his life and couldn't finish his dissertation. Only at the end of the novel, once Jack has experienced a series of events that somewhat reflect Mastern's life, can he actually finish his dissertation and explain the "truth" of his ancestor's life.